Protecting-hood for spark-plugs.



PATENTED FEB. 11, 1908.

D. B. MILLS. PROTECTING HOOD FOR SPARK PLUGS.

APPLICATION FILED FBB.2, 1906.

fig 3.

M AZ/T/VESS'ES: fufafw f DAVID B. MILLS, OF EAST ORANGE, NEW JERSEY.

PROTECTING-HOOD FOR SPARK-PLUGS.

Specification of Letters Patent.

Patented Feb. 11, 1908.

Application filed February 2. 1906. s i l N 299,101.

To all whom it may concern:

- Be it known that I, DAVID B. MILLS, a citizen of the United States, residing at East Orange, New Jersey, have invented certain new and useful Improvements in Protecting- Hoo ds for Sp ark-Plugs of which the following -is a clear, full, and exact description.

The object of this invention is to provide a protector for electric terminals particularly for the central terminal of spark plugs which will prevent the formation of'a conducting film, through moisture or otherwise, from the terminal to a part of opposite polarity.

In carryin out my invention I make use of a hood whic '-covers a terminal of the plug and incloses some of the insulating shank of -the spark plug, and I provide a passage either at thetop or near the top of the hood for the passage of a conductor terminal for contact with the spark terminal. In general I the hood is so formed that when-one terminal is therein, the other may be inserted into the hood to contact with the first and preferably resiliently engage it. v

In my preferred embodiment of this invention'I provide the conductor with a terminal clip which may be sprung into contact with the terminal of the plug after the hood is placed over the terminal post and the hood thus locked in place upon the post by means of said terminal clip of the conductor. I may also provide a means for sealing the openin through which the conductor passes, and thls sealing means in my preferred construction consists of an elastic sleeve fitting the conductor, its other end adapted to fit over a shoulder surrounding the passage for the conductor, and thus hold theconductor 4 gles to terminal within the hood.

' In the accompanying drawings, Figure 1 is a sectional side elevation of my improved hood with the plug and terminal in place; Fig. 2 is a bottom plan of the same with the plug removed and the conductor detached;

and Fi 3 an outside elevation at right an- Fig.- 1 of the hood. In the specific embodiment of my invention illustrated herein I have shown a plu provided with a threaded socket lprovide with a nut 2-from which protrudes the insulating shank 3, surmounted by the terminal 4 provided with'a lesser portion 5 between two major portions 6 and 7.

The hood 8 consists ofthe three chambers, the first chamber '9 formed of hexagonal cross section, the second 10 of less cross section and substantially circular, and the thirdand parallel to the narrow passage 13.

The conductor 21 is capped by a ferrule 22 to the end of which a terminal clip 23 is secured which is formed of one flat part having two arms 24, 25 and provided between them with an opening 26, entrance to which by the post may be secured by first passing a restricted portion 27 between the arms. This clip may have one end 28 turned at right angles to its body and secured by that end to the ferrule 22, both ferrule and end 28 being provided with openings to receive the-wire of the conductor 21 to permit its being soldered thereto, as shown at 29. The elastic sleeve 30 is so proportioned that its end 31 may tightly grasp the conductor 21 while its end 32 is flared out bell shaped and is of greater diameter so that it may'readily beslipped over the bushing 14 and held in the groove 15 to seal the o ening for the conductor and also tend to ho d the conductor in place.

When the post is in position in the hood the flat terminal clip may be inserted through the narrow passage, so as to cause the arms to grasp the lesser diameter of the post, which is substantially opposite. the passage,

and the ferrule to occupy a position within the hollow portion of the bushing-like proj ection of the hood. The plug, hood and clip are thus locked together. The larger diameter of the elastic sleeve is now drawn over the bushing-like projection and its end caused to engage the circumferential groove, thus acting as a'means for holding the terminal and conductor within the hood.

I am aware that screw caps of insulating material have heretofore been used to rotect electric terminals, particularly for 'gh tension =currents, but I am not aware that insulating hoods with plain walls that merely fit around and do not positively engage the The bushing-like projection 14 1 for a conductor, said hood being sup orted by the lug on which it rests said hoo being removiible from said plug by direct pull.

, 2. A spark plug in combination with an insulating protecting hood having a central chamber of greater diameter at its base than the widest part of said plug, and provided throughout with plain non-enga ing walls and a passage through the wall ,0 the hood for a conductor, said hood being supported by the plug on which it rests, and means for seahng the passage for the conductor said hood being removable from said plug by di- Y rect pull.

3. In combination, a spark plug having a terminal ada ted to be connected with a conductor terminal b resilient engagement, a

conductor termina adapted to so engage said plu terminal, an insu ating hood substantia y fitting said plug and open at itsbottom, and provided with a plain non-engaging interior wall, a passage in the wall for the insertion of the conductor terminal, said hood supported by said lug said hood being removable from said p ug by direct pull.

4. In combination,a spark plug having a' terminal adapted to be connected with a conductor termmal b resilient engagement, a conductor 'termina ada ted to so engage said plu terminal, an insu ating hood substantia y fitting said plug and open at its bottom, and provided with a plain non-engaging interior wall, a passage in the wall for the insertion of the conductor terminal, said hood supported by said" plug, and an elastic sleeve secured tothe conductor and adapted to be detachably secured to the hood around said pas a e for the terminal said hood being re- 0 a le fromsaid lug by direct ull.

5. A protecting ood for a spar plug ter minal having an open end to receive the terminal and a'passage through its wall'for a conductor, and a bushing-like proj ection surrounding saidpassage provided with a hollow recess, near one end of which the passage o ens. i a

6.. protecting hood for a spark'plug terminal having an open end to receive the terminal, and a passage through its wall for a conductor, said hood having a central chamber of three parts, one-adapted to fit the bodyof a plug, one to fit its shank and a third of greater diameter than the second, with which third the passage connects.

7 A protectmg hood for a spark plug terplug by direct pull.

-minal having an open end to receive the ter* minal and a passage through its wall for a conductor, in combination with means for securing the hood to a plug and terminal upon the mere passing of the terminal through the passage when the hood is inclosing a plug.

8. A protecting hood for a spark plug terminal having an open end to receive theterminal and a passage through its wall for a conductor, and a bushing-like projection surrounding said passage, in combination with a conductor and an elastic sleeve thereon, one end of which is adapted to engage said bushing-like projection.

9. A protecting hood for a spark plug ter- 30 minal having an open end to receive the terminal, and a passage through its wall for a conductor, said hood having a central cham ber of three parts, one adapted to fit the body of a plug, one to fit its shank and a third of greater diameter than the second, with which third the passage connects, and a circumferential groove on said bushing-like projection.

10. A spark plug, an insulating protecting s0 hood supported by the plug of .eater diameter than the widest part of t e plug, said hood havinga'plain non-engaging interior Wall, and an open end adapted to receive the terminal, and a passage through its wall for a conductor in combination with aconductor" terminal and an elastic means for holding it in place in the passage said hood being removable from said plug by direct pull.

11.. A spark plug,-an insulating protecting hood-supported bv the plug of eater diameter than the widest part of t e plug, said hood having a plain non-engaging interior wall, and an open end adapted to receive the terminal, and a passage through its wall for a conductor in combination with a conductor terminal and an elastic means for holding it in place in the passage, said elastic means comprising a sleeve surrounding said conductor and engaging the hood said hood be ing removable from said plug by direct pull.

12. A spark lug, an insulating protecting hood supporte by the plug of greater diam- .eter than. the widest part-of the plug, said hood having'a plain non-engaging interior wall, and an open end adapte to receive the terminal, and a passage through its wall for a conductor in combination with a conductor terminal and an elastic means for'holding it in place in the passage, a bushing on' the h'ood, said elastic means comprising a sleeve 'engaging the conductor at one end, and.

, adapted to engage the bushinglat the other end said hood being remova e from said prising a shank of insulating material pro vided at its 11 er end witha terminal, a protecting cap 0 insulating material adapted to I 13. In combination, a spark plug comfit over said plug and provided inlts side 130 hood with a passage, and a conductor terminal adapted to be inserted through said passage,

said two terminals being adapted to resiliently engage each other, said terminal of the conductor when engaged passing through the hood in a direction to lock it from removal. v

14. A spark plug having a terminal at its upper end, a conductor terminal, means for resiliently securing said terminals together, and a hood of insulating material provided with passages one for each of said terminals at substantially right angles to each-other, whereby when one terminal is in'place in the hood the other may be passed into said hood and the two caused to engage, said terminal of the conductor when engaged passing throu h the hood in a direction to look said roin removal from said plug.

15. An insulating protecting hood adapted to fit over a spark plug terminal having an open end to receive the terminal, and a passage through its wall for a conductor, said passage being so located in the hood that a terminal inserted therein will engage a plug terminal within the hood, said conductor terminal when engaging the plug terminal forming a locking means to revent the removal of the hood from the p ug.

16. A spark plug, its terminal, an insulating protecting hood therefor adapted. to fit over the spark plug terminal, said hood having an open end to receive the terminal, and a passage substantially at right angles with the axis of the hood through the wall of the hood for a conductor, said terminal of the plug resting against and supporting said hood with the plug terminal opposite said passage.

Signed at New York city this 30th day of January 1906.

DAVID B. MILLS.

Witnesses:

F. WARREN WRIGHT, EMERSON R. NEWELL. 

